/*******************************************************************************
 * Copyright (c) 2019, 2019 IBM Corp. and others
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] http://openjdk.java.net/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 *******************************************************************************/
package com.ibm.j9ddr.vm29.pointer.helper;

import com.ibm.j9ddr.CorruptDataException;
import com.ibm.j9ddr.vm29.pointer.generated.J9ShrOffsetPointer;
import com.ibm.j9ddr.vm29.types.UDATA;
import java.lang.reflect.InvocationTargetException;

public class SharedClassesMetaDataHelper {
	public static int getCacheLayerFromJ9shrOffset(J9ShrOffsetPointer j9shrOffset) throws CorruptDataException {
		int layer;
		try {
			UDATA layerUDATA = (UDATA) j9shrOffset.getClass().getMethod("cacheLayer").invoke(j9shrOffset);
			layer = layerUDATA.intValue();
		} catch (NoSuchMethodException e) {
			layer = 0;
		} catch (InvocationTargetException e) {
			Throwable cause = e.getCause();
			if (cause instanceof NoSuchFieldError) {
				layer = 0;
			} else if (cause instanceof CorruptDataException) {
				throw (CorruptDataException) cause;
			} else if (cause instanceof RuntimeException) {
				throw (RuntimeException) cause;
			} else {
				throw new CorruptDataException("Error getting the cache layer from J9ShrOffsetPointer", cause);
			}
		} catch (IllegalAccessException e) {
			throw new RuntimeException("Error getting the cache layer from J9ShrOffsetPointer");
		}
		return layer;
	}
}
